Puppet head



Aug s, 1933. k. F. emu. v1,921,502

PUPPET HEAD med march 24. 195m 3 suma-sheet 2 j MQW-:4 ha

INVE NTD R= K. F. BRILL 1,921,502

Aug. 8, 1933.

PUPPET HEAD Filed March 24 1950 3 Sheets-Sheet 5 NVENTR Patented Aug. 8,1933 Application vMarch 24,

. and in Germany leso, Asensu No. 438,558,

March 27, 41929 This invention relates to a` puppet head which is'especially suited for lathes` designed to" work large and lheavy works.

When turning ofi works alterations of the length of the work'occurowingy to thev'heating connected with thecutting oi of chips and rowingto the tensions. f

As the tendency is, e vchip' thicknesses by means of high grade toolsteels, the alterations 'of length are 'further creased. They callforthmore or less great forces,

-which lhave to be'. taken up bythe-center-.of the puppet head ,and by-the face platev and, express themselves in increased stressing ofthedriving spindle, puppet head bearing and increased power demand. Adeformation of thevwo'rk itself, specially of long works, is furthercaused, which unjfavorably influences the accuracy of the working'.Especially the .dead center i'sbeing 'destroyed very soon owing to theincreased friction.y Y

This invention has for its object the avoidance of the. saidinconvenience by'taking into consideration they construction of thepuppet head the alterations in length of the Work occuring during thetreatment, the facilitating of the fixing of e i the work by reducingthepforce to be exerted `*by the hand owing to hydraulic' pressing ofthe dead center into the centering bore of the worlahand'k the securingof the'work inthe fixed position against dropping out by limitingthefshifting movement of the hydraulically'moved'elemenu -Furtherobjectsand advantages ofthe invention will behereinafter explainedandare illustrated in the `accompanying drawings which show severalembodiments of 'the invention',

Fig. 1 is a partialv longitudinal sectionthrough the preferred form ofconstruction, in which the pressure liquid is supplied from arseparate4source.

Fig.v 2 shows the puppet. head Fig.-` 1k partly in cross section on line2,-2 of Fig. 1 fon,enlargedA Y scale.

Fig. 3 is a partiallongitudinal section ythrough a puppet head, in whichtheliquid pressure" is produced by means of a displacer. y 5 Figs. 4 and-5 show part longitudinalsections through puppet heads with air bufferconnected f to the pressurel chamber.

' Figs. 6 and 7 are part' longitudinal sections through puppet headswithfcontact manometer for regulation of the liquid pressure, A liquidbeing supplied to the puppet head shown in Fig. 6 through a separateconduit, whereas in the puppet head shown in Fig. 'l the pressure oftheliquid is produced by means of the displaccr.l

to obtain always greater i not'amou'nt to more than half the depthtowhich ,6,ftlrie,front pin part 'being shifted lafter a travel"amountingto the and front pin parts. This mechanical operationvservesiorthe introductionof the dead centre into the centering borelcentre ispressedi-nto'the centering bore of the .f the casing -3 servesthe pressure" r4121er the pressure liquid an which permits ofthelpressure Fig'. 8 is an end elevation of the puppet head showninFig. 7.f f v .In the forms of construction shown in Figs. 1,

`2 and 4 the dead center 4 is arranged in the pin 'partl. constructed asplunger. Behind the .part 1 00 a'chamber-'I'is arranged, which isdesigned to hold pressure liquid."` The movability of the pin part v1carrying the-dead centre standing under the influence of the pressureliquid in the chamber is during the' `treatment atleast equal to themaximum expansion "of the fixedv work and 'amounts at the futmost toabout. oneA half of the depth to which the dead center engages with thecentering bore of the work. The chamber 'I is formed by the subdivisionof thecasing 3 by -jrneans of-a stufling box 9 provided in the chamberand ,formed by an annular projection in the casing. n. rThe packingofthepart 1 is'designated by'l and that oftheannular projection vby 1i'.`'I'hepart 1 is secured against rotation byja key. 28 xed in'this partand for which a'groove 29 is f provided inthe casing 3,- s o that theaxial dis-` placement is not impeded.- -In the .rear 'pin part 2thespindle 5 flttedwith ahandwheel 6 engages,

which has a collar 5' 'and which is securely held in 8 r vthe casing bymeans of an annular disc 5", xed

by means'of screws not'shown. The pinpart 1 has an extension 8 extendingtowardsgthe rear pin part 2 and engaging with a-bore of the latter. Therear pin part2 rand theextension 8 are 'connected with each other by aconnecting element, consisting of-a wedge 10, .extending through "therear part 2 and through the extension 8. The

clearance .14 of the wedge 10l in the extension does thef dead centre4engages withthe centering bore 30 ofV the work 3.1. The rear pin'part 2is mechanically operated by'rotation of the hand wheel clearance 1'4between the rear of the work. The dead work by the pressure liquid. Anaperture 32 in for the removing of the coupling element 10. Amanometerl-isl connected tothe pressure. chamber?? and serves forcontrolling theliquid pressure A hand pump 11 is provided forthe-production of the` pressure. Instead ofahand pump a mechanicallydriven pump may evidentlyibe provided. inthe conduit `elementis located,liquidl riddim! and flowing forward inthechamber 'Land itfconsists no. n

controlled by `springs 37` and have shafts merging into screw-bolts 38.On these shafts nuts 39 serving as abutments for the springs 37 arescrewed so that they permit of altering the spring tension. The otherabutments for the springs are formed by the casing of the pressureregulating element, a disc being eventually interposed. The pressure towhich the spring is adjusted can be read on a scale 40. By the variablespring tension it is possible, to adjust the pressure regulating elementin accordance with any ydesired liquid pressure in the pressure chamber.The portion of the conduit supplying the liquid is connected at 41,whereas the portion discharging the liquid is connected at 42. In thislatter portion, which leads to the collecting cup of the pump 11, thethree-way cock 33 is arranged. A

- and2the bore 48 extends in the pressure regulating element in lateraldirection. To this ,bore 48 the manometer 26 is connected and adapted tobe shut off from the pressure chamber by a cock 49. An air cock 50enables one to connect the, air buffer with the atmosphere. In the formof construction shown in Fig. 4 the manometer 26 is condraining pressureliquid. Instead of the, pump 11 a pressure accumulator can be provided.The pressure 'chamber .7 can also be connected with a spring vloadedpressure accumulator, thespring pressure being adjusted in accordancewith the pressing-on lpressure vto be obtained.. WhenV such anaccumulator is provided, separate valves are no longer necessary. Inthis case the accumulator forms already the element, which lpermits ofthe moving back and forward of the pressure liquid in accordance withthe dead centre displacement required for the work,v without substantialpressure alteration. As such a form of construction is clear withoutfurther explanation, it is not shown in the drawings. i r l The form ofconstruction illustrated in Fig. 6 differs Vfrom that shown in Fig. 4 inthat instead of the simple manometer a Contact manometer57xof known typeis provided, the electric wires 70 of which lead to a motor not shown,which drives a pump for the production of a pressure liquid but Aalsonot shown. Motor and pump may be ar'- ranged on'the puppet head insteadof the hand Y pump 11 shown in Fig. 2.

a nut, and on which a hand vwheel 19 for the mechanical feedV ismounted. A collar 18' enables one to x in the pin casing the sleeve 18by means of the annular disc 15. A displacer 20 is arranged in thehollow spindle 17 for producing the liquid pressure in the pressurechamber 7, said displacer being operated by the screw spindle 21 bymeans of a hand wheel 25.

In the form of construction shown in Fig. 3 the device permitting of theyielding and displacing `of the pressure liquid in accorda rice with thedead centre displacement caused by alteration of length of the work isobtained in that a spring 22 is interposed between the displacer 20 andthe screw spindle 21. A manometer 23 is connected with the pressurechamber 7.

In the puppet head shown in Fig. 5 an air buffer 53 is connected withthe pressure chamber 7 and. serves as pressure regulating element. Themanometer 54 is arranged on the air buffer and can be shut off from thepressure by 'means' of a cock 55. The displacer 20 and the screw spindle21 are made in one piece.

In the forms of construction shown in Figs. 3 and 5, the pin casing 3has 'an opening 24 in consideration of the shifting movement of the pinpart 2" at the mechanical feed. The packings on the pin part 1' and onthe mechanically moved pin part 2 are designated by 56. The wedge 10extends through the pin part 2 and through the pin part 1' and it has inthe pin part 2" a' clearance 14. This clearance does not amount to morethan half the depth at which the deadv centre engages with the centeringbore of the-work.

In the form 'of construction shown in Figs. 7 and 8 a contact manometer58 of known type is substituted for the manometer 54 of Fig. 5 andconnected by leads 59, 59', 59" with a motor 60 adapted to be switchedin in both directions of rotation. The` sleeve 18, constructed as nutfor the screw spindle 17, isdriven through av worm gear 61, operated bya'hand wheel 19. A spur Wheel 63 ,is positively connected `by a key 64with the spindle 21 of the displacer 20, said spindle being. capable ofshifting in axial direction during the rotation, owing to its longgroove65. A pinion 66 on the shaft of the motor meshes with the spurwheel 63.. The motor "revolves in the one or other directions, accordingto Whether the contact manometer closes the electric circuit through thewires 59 and 59' or through the wires 59 and 59T', so that the displacer20 is pulled out or pushed in according to requirement. Ihe hand wheel25 on' the displacerspindle 21 serves for the xing and for the operatingby hand. An optical or acoustic signal may be connected with theelectric circuits, said signal being lighted or sounded, as soon as theadjusted pressure ofthe pressure liquid alters.`

The operation of the puppet head constructed according to the inventionis as follows:

"The dead centre is inserted by rotation of the hand v fbe'elf (Figs-1and 4) or of the hand wheel r19 (Figs. 3 and 5) or of the handl wheel19' (Figs. 7 and 8) into the centering bore 30 of the work 31, themechanicallyperated pin part 2 and the' hydraulically operated pin part1 being pushed forward. During the -mechanical feeding the three waycock 33 connects, in the forms of construction shown in Figs. 1, 2, 4and 6, the pressure chamber 7 with the collecting cup of the pump 11, asshown in Fig. 2, in order that at the forward moving of the pin part 1liquid may be sucked into the pressure chamber 7 and forced out of thesame at the mechanical pulling back. After the completion of themechanical pushing forward the cock 33 is turned in the direction of thearrow 66, so that the pressure chamber 7 is cut oiand the bore 67 of thecock registers with the conduit 12. ter the dead Centre has beenintroduced into the width of the clearance.

'chamber '7, whereas in centering bore of the work, the hydraulicallyshiftable pin part l is put under hydraulic' pressure, whereby the deadcentre is pressed into the centering bore.

In the construction 6 pressure liquid is conducted into the pressureFigs. 3, 5, '7 and 8 the pressure is produced by the plunger penetratinginto the pressure chamber filled with liquid. At the mechanicalintroduc-y ing of the dead centre into the bore a surface 68 of thewedge 10 and a surface 69 of the hydraulically operated pin part l are`pressed the one against the other. At the pressing-inl these sur facesseparate. In order to completely utilize the clearance, the mechanicalpin part is pulled back, after the pressing-in, a distance equal to theThe manometery permits of controlling whether a sufficient pressing-inpressure has been attained. If, when the work has been treated,alterations Vof length of the work occur, which require a pressureincrease in the pressure chamber '7. yielding or displacing v of 'thepressure liquids takes place, according to whether the work expands orcontracts, this yielding or advancing being effected by the pressureregulating elements, so that the pressing-in pressure is never alteredin a manner worth mentioning.

In the yforms of construction shown in Figs. "l, 2, 4 and 6 the pressureequalization is efectedby the pressure regulating element 13, throughwhich liquid can flow only in the direction of the arrow 34, and thevalve 360i which, permitting the return flow from the pressure chamber,can be adjusted to a certain pressure as already stated above. If theexpansion work is completedand the `work contracts, the valve 36 remainsclosed, flows through theV valve 35 Hinto the pressure chamber '7.

In the form of construction shown in Fig. 3

a pushing back of the displacer, in oppositionv tothe spring 22, takesplace at pressure increase, i. e. expansion in the work. Inversely thedisplacer is again pushed forward by the spring at the subsequentcontraction of the work, so that the necessary pressing-in pressure isalways at disposal.

If for any reason whatsoever the pressure' of the liquid should suddenlyfail or drop, the centre can never disengagel completely from thecenter-'Y ing bore, and the work cannot drop out, as the clearance 14between the hydraulically operative pin part and the mechanicallyoperative pin part does not amount tomore than half of the engagingdepth also neveramount to more than this half The air buffer connectedto the pressure 'chamber, according torFigs. 1, 6 and 7 neutralizesshort pressure increases, for instance vibrations atv rough turning upto the pressure limit determined by the overloading valve of by thecontact buffer may evidently be further connected toa `compressed airconduit or an accumulator of compressed air, in the conduit of which,'co'r" responding with the pressure regulating element 13 in the liquidconduit in the form of construcshown in Figs. 1, 2, 4 andythe'construction shown in in length of the whereas pressure liquid saidcasing,

rier parts of the dead centre, so that an accidental backward movementof theldead centre can v onthesame side of said rear part of saidcarrier tion shown'in Fig. 2, a pressure regulating element is built,which equalizes fluctuations of pressure. v y l 'Ihe form ofconstruction shownin Fig. 5 and in Fig. 3 is specially suitable forturning' lathes of medium size.

The contact manometer connected with thev air buffer in theform ofconstruction shown in Fig. 6" switches in at pressure drop a motor notshown, which drives a pump, supplying a pressure liquid for the pressurechamber.

In the form o'f construction shown in Fig. l the contact manometerswitches in a motor for both directions' of rotation, which either pullsout cr pushes in the displacenZO-according to requirement.A The contactmanometer might be directly connected with the pressure chamber.

For releasing the work, the pressure,l is removed from thepressurechamber andgthen the dead centre pulledback mechanically. .v

The releasing ofthe work ca Y' effected in the form of construe `n shownin Figs. 3, 5, 'Z and 8 also by mechanical pulling back without apressure drop.

The invention is not limited to the forms of construction shown.

1. A puppet head, comprising in combination a casinghaving a centrallongitudinal bore, a two part dead centre carrierin said casing composedofr a -front .part and a rear part longitudinally shiftable in saidcasing, an extended axle extending towards thc interior of said casing.and having a screw thread, a dead centre pin carried `in the front endof said carrier part the rear part of said carrier having a screwthreadengaging the screw thread of saidextended axle a wheel on the end ofsaid casing adapted to rotate said extended axle'and shift said rearcarrier part in a pressure liquid chamber at the rear end of said frontcarrier part adapted tos act on the rear endo'said front carrier part, acoupling element connecting said front and rear carywith play extendingplunger like into said chamber adapted to transmit the movement 'of saidrear carrier part imparted by said extended axle to said front carrierpart and to press affdisplacement of said front carrier with said deadcentre pin according length of the work.

2. A puppet head as rspecified in claim 1, in

to the alterations in l' which an air cushion is connectedto the liquidlled pressure 'chamberacting on the front carrier part accommodating thedead centre pin front carrier part on which said liquid acts, said aircushion acting on said liquid and having the same pressure as that ofthe liquid.

`3. A puppet head, comprising in combination, a casing having a centrallongitudinal bore, a two part dead centre carrier in said casingcomposed of a front part and a rear part longitudinally'shiftable insaid casing, an extended axle extending vtowards the in-terior of saidcasing and having a screw thread. a dead centre pin carried in `thefront end of having a screw thread engaging the screw threadfof saidextended axle a wheel on the end of said casing adapted toropart in saidcasing, a stuffing box in said casing :said carrier part the A depth ofengagementof thedead centre said casing into two parts, a piston rodextensio'i'i on therear end of said front carrieripart exwith play vtothe front end of'lsaid reaLca'rrierI part, a chamber lled with liquidbetweenthe rear side of said front carrier part and the front vof saidstuiiingbox adapted to act onsaid'front carrier part` in the ieeddirection, .and a device connected to said chamber adapted to allow. theyielding and returning of the liquid in said charn-` ber and adisplacement of said front carrier part with said dead center pinaccording to the alterations in length of the workpiece during theworking.

4. A puppet head as specied in claim 1, in which the hydraulicshiftability of the front carrier part relative to the rear carrier partis equal to at least the maximum expansion of the workpiece and does notexceed one half of the pin in the centring bore in the workpiece.

`5. A puppet head as specified in claim 1, in which the play betweenthel two carrier parts rendered possible byv the coupling element doesnot exceed one half of the depths of engagement of the dead centre pinin the centering borein the workpiece.v

6. A puppet head as specified in claim 1, comprising in combinationVwith the deadicentre pin, the front carrier part and therearcarrierpart, a transverse pin extending throughl both of saidcarrier parts connecting said carrierparts with a certain amount of'play not exceeding one half v of the depth of engagement of said `deadcentre pin in the centering bore in the workpiece;

7. A puppet head, comprising in combination a casing, a dead centre, atwo part dead centre carrier shiftable in saidcasing composedI of a.front part carrying said dead centre anda shiftable rear .part having ascrew thread,l an extended axle `extending into said casing and having ascrew thread engaging the screw thread of said rear part, va wheelon-said axle at the Y, rear end of` said casing adapted to rotate saidaxle to shift said rear partv in said casing,l a couplingelement'connecting said carrier parts with play adapted to transmit themovement of said rear carrier part to said front carrierpart, said irontcarrier part being-constructed as cylinder i and containing pressureliquid and said rear part constructed as plunger adapted to press saidfront part against the work piece, and a device connected to saidcylinder adapted to allow the Y liquid to automatically escape from andreturn into said cylinder according tol the variations in length of theeration.

l. `8. A'puppet head, comprising `in combination a casing, a deadcentre, a, two part dead centre carrier shiftable in said casingcomposedof a front part carrying said dead centre and a shiftable rear parthaving a screw thread, an extended axle extending into said casing 4andhavingl a screw thread'engaging the screw thread of said rear part, awheel on said axle-at the rear ,end of :said casing adapted torotate'said axle to shift said rear part in said casing, a couplingelement connecting said carrier parts with play adapted to transmit the`movement of said rear carrier part to said front carrier part, saidfront carrier part being constructed as cylinder andrcontaining pressureliquid and said rear part constructed as `plunger adapted. to presssaid,front part work piece during the working op-v between said carrierparts dividing the bore in" against the work piece, and a deviceconnected to said cylinder adapted to allow the liquid to automaticallyescape from and return into said cylinder according to the variationslin length of thev work piece during the Working operation said frontpart having a longitudinal bore with screw thread at its rear end andcommunicating with said cylinder, a"displ`acer in said bore, a screwspindle engaging in the screw thread of said bore carrying saiddisplacer on its front end extending through said wheel on the rear endof said casing, and a second wheel on Ithe rear end of said casing, adead centre, a two part dead centre carrier ,shiftable in said casingcomposed of a front part carrying said dead centre and a shiftable rearpart having a screw thread, an extended axle extending into said casingand having a screw threadengaging the screw thread of said rear part awheel on said axle at the rear end of said casing adapted to rotate'said axle to shift said rear part in said casing, a coupling elementconnecting said carrier parts with play adapted to transmit the movementof said rear carrier part .to said front carrierpart, said front carrierpart being constructed as cylinder and containing pressure liquid andsaid rear part constructed as plunger adapted to pressv said front partagainst the work piece, a liquid chamber in said casing adapted to acton the rear endl of said front carrier, a device connected to saidchamber adapted to allow an automatic yielding and displacing of theliquid in said chamber and a moving back of said front carrier partaccordin'g'to the variations in length of the workpiece, a pressuregauge connected to said pressure chamber adapted to indicate thepressure in said chamber, electric contacts `in said pressure gauge, a.circuit con'-, nected to said contacts adapted to be closed by` .acasing, a dead centre, a two part dead centre carrier shiftable in saidcasing composed of a front part carrying` said dead centre and ashiftable rear part having a screw thread, an extended axle extending,into said casing and having a screw thread engaging the screw thread ofsaid rear part, a wheel on said axle at the rear end' of said casingadapted 'to rotate said axle to shift saidrear part in said casing, acoupling element 'y connecting` ysaid carrier parts with play adaptedtotransmit the movement of saidy rear carrier part to said front carrierpart, said front carrier part being constructed as cylinder andcontaining pressureliquid and said rear part constructed as plungeradapted to press said front partl against the work piece, and a Adeviceconnected to said cylinder adapted to allow the liquidto automaticallyescape from and Vreturn into said cylinder according to the variationsin length of the work piece during the working operation said frontpartl having a longitudinal bore with screw thread at its rear end'andcommunicating with said cylinder, a displacer in said bore, a screwspindle engaging in therscrewv thread of said bore carrying saiddisplacer on its front4 end extending .spindle-adapted to displace saiddisplacer in said v v pressure space increases to close one of saidcircuits and cause said motor to rotate in one direction to withdrawsaid displacer from said space when the pressure in said space drops toclose the other of said circuits to cause said motor to rotate in theother direction to push said displacer further into said space.

KARL FRIEDRICH BRILL.

